Abstract: Process of mixing a fugitive plasticizer, e.g., ethylene carbonate, with moist particulate polyacrylonitrile then removing the water enabling adjustment of the melt viscosity for extrusion of the polyacrylonitrile into film, fiber, pellets and shaped articles. Stretching and heating the extruded polyacrylonitrile film or fiber causes the fugitive plasticizer to exude and vaporize from the film or fiber, carrying with it any remaining acrylonitrile monomer. The resulting film or fiber exhibits substantially increased molecular weight, thus enhancing the tensile strength and barrier properties of the polyacrylonitrile product. The process also produces polyacrylonitrile foam products. A novel cross-linking agent for polyacrylonitrile, divinyloxybutane, is disclosed. Thermostabilizing agents for polyacrylonitrile, N-maleimides and stilbene derivatives, are also disclosed.

Abstract: Process of mixing a fugitive plasticizer, e.g., ethylene carbonate, with moist particulate polyacrylonitrile then removing the water enabling adjustment of the melt viscosity for extrusion of the polyacrylonitrile into film, fiber, pellets and shaped articles. Stretching and heating the extruded polyacrylonitrile film or fiber causes the fugitive plasticizer to exude and vaporize from the film or fiber, carrying with it any remaining acrylonitrile monomer. The resulting film or fiber exhibits substantially increased molecular weight, thus enhancing the tensile strength and barrier properties of the polyacrylonitrile product. The process also produces polyacrylonitrile foam products. A novel cross-linking agent for polyacrylonitrile, divinyloxybutane, is disclosed. Thermostabilizing agents for polyacrylonitrile, N-maleimides and stilbene derivatives, are also disclosed.

Abstract: A process for providing extrudable polyacrylonitrile compositions. Dry, particulate polyacrylonitrile having a moisture content of less than about 1.5 percent is mixed with a liquid plasticizer such as ethylene carbonate or propylene carbonate at a mixing temperature of about 140.degree. C. to about 180.degree. C. This process produces an extrudable polyacrylonitrileplasticizer composition which can be extruded to form film, fiber or other extruded or co-extruded products.

Abstract: Process of mixing a fugitive plasticizer, e.g., ethylene carbonate, with moist particulate polyacrylonitrile then removing the water enabling adjustment of the melt viscosity for extrusion of the polyacrylonitrile into film, fiber, pellets and shaped articles. Stretching and heating the extruded polyacrylonitrile film or fiber causes the fugitive plasticizer to exude and vaporize from the film or fiber, carrying with it any remaining acrylonitrile monomer. The resulting film or fiber exhibits substantially increased molecular weight, thus enhancing the tensile strength and barrier properties of the polyacrylonitrile product. The process also produces polyacrylonitrile foam products. A novel cross-linking agent for polyacrylonitrile, divinyloxybutane, is disclosed. Thermostabilizing agents for polyacrylonitrile, N-maleimides and stilbene derivatives, are also disclosed.

Abstract: Solvent system for polyacrylonitrile polymers comprising nitromethane, water and fluoro alkanol. The solvent enables a high concentration of polymer to be dissolved without the solution being too viscous to cast as a film or to spin as a fiber. The solvent is sufficiently soluble that it can be removed substantially completely from the resulting film or fiber with consequent advantages of leaving no toxic residue and of not discoloring the end product.

Abstract: Vinyl halide resin compositions having improved fire resistance are formed by the introduction into said compositions of a small amount of a reactive hydroxy group-containing polyvalent metal salt of a phenol-aldehyde resin of the novolac type. The resulting vinyl halide resins evidence increase charring of the surface when exposed to heating by a flame or undergoing combustion, the surface char acting as a barrier to heat transfer from the flame and retarding the flow of volatile gases from the pyrolyzing resin.